In 1811 William Allan established a company of timber merchants in the small town of Eyemouth in Berwickshire. Allan Bros. moved to Berwick-Upon-Tweed, Northumberland in 1851, and the company remains there to this day. In 1894 the business was incorporated as a limited company.
In 1914 the firm was described as timber merchants and saw millers specialising in mouldings and joinery. The company had around 150 employees at this time.
In 2007 Allan Bros. became part of the Inwido Group, one of Europe’s leading manufacturers of timber windows and doors.